Thanks, Jeremy. I guess I'm not running as a service, so I'm probably fairly safe. I did just notice that the ntpd is using /etc/ntp.conf and it has this info about ntp servers: -----begin ntp.conf excerpt on next line--------- # Specify one or more NTP servers. # Use servers from the NTP Pool Project. Approved by Ubuntu Technical Board # on 2011-02-08 (LP: #104525). See http://www.pool.ntp.org/join.html for # more information. server 0.ubuntu.pool.ntp.org server 1.ubuntu.pool.ntp.org server 2.ubuntu.pool.ntp.org server 3.ubuntu.pool.ntp.org # Use Ubuntu's ntp server as a fallback. server ntp.ubuntu.com -----end ntp.conf excerpt on previous line--------- This machine is at umn.edu, so I should probably add the local time servers, which I guess are these: server 128.101.101.101 server 134.84.84.84 (a.k.a. ntp.umn.edu; Same as the nameservers in /etc/resolv.conf) Mike On Wed, 9 Sep 2015, Jeremy MountainJohnson wrote: > I was using ntpdate (the smallest ntp client) with crontab for awhile > too. This was mostly on an older NAS a few years ago. Now, I stick > with running the daemon configured as a client only (for servers and > workstations). As you correctly stated, it's a fairly small footprint, > and the gain in precision makes it worth in most cases I can think of. > Also have been running constantly on my rasp pis now for a few years > (you almost have to with the lack of time retention on them). > > So, IMO, not much performance / memory gleaned using the minimal > client like the old days (even then it was pretty minimal). You lose a > little ground on security if not configured properly (ie. as a server > on a lax network intended to be configured as a client only). > > -- > Jeremy MountainJohnson > Jeremy.MountainJohnson at gmail.com > > > On Wed, Sep 9, 2015 at 12:10 PM, Mike Miller <mbmiller+l at gmail.com> wrote: >> For years I have been using something like this in a root crontab to adjust >> the time every 6 hours: >> >> 10 4,10,16,22 * * * /usr/sbin/ntpdate-debian >> >> On this machine it was going off by about 0.17 seconds every 6 hours and it >> was pretty consistent: >> >> 7 Sep 16:10:10 ntpdate[11932]: adjust time server 91.189.89.199 offset >> 0.172249 sec >> 7 Sep 22:10:09 ntpdate[13949]: adjust time server 91.189.89.199 offset >> 0.173074 sec >> 8 Sep 04:10:10 ntpdate[15490]: adjust time server 91.189.89.199 offset >> 0.174787 sec >> 8 Sep 10:10:09 ntpdate[18482]: adjust time server 91.189.89.199 offset >> 0.169422 sec >> >> Then I noticed that on a newer Ubuntu installation I didn't have the >> crontab, but the timing was even better. I'm pretty sure that newer Ubuntu >> installs let the user to choose to set date/time "automatically," and that >> was what I had chosen. >> >> So I had to wonder what it *really* was doing. I think it was running ntpd. >> >> USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND >> ntp 23926 0.0 0.0 39832 2264 ? Ss Sep08 0:01 >> /usr/sbin/ntpd -p /var/run/ntpd.pid -g -c /var/lib/ntp/ntp.conf.dhcp -u >> 119:128 >> >> So I installed the ntp package like so: >> >> sudo apt-get install ntp >> >> That automatically set everything up and started it running. It can be >> called with the service command to ntp... >> >> sudo service ntp [start stop restart] >> >> ...which runs the script here: >> >> /etc/init.d/ntp >> >> That seems to keep the clock set very precisely. >> >> I guess the downside is that it is always running, but it if is using no >> more than 2.3 MB, that isn't a problem. >> >> Is this what everyone is doing these days? >> >> Mike >> _______________________________________________ >> TCLUG Mailing List - Minneapolis/St. Paul, Minnesota >> tclug-list at mn-linux.org >> http://mailman.mn-linux.org/mailman/listinfo/tclug-list > _______________________________________________ > TCLUG Mailing List - Minneapolis/St. Paul, Minnesota > tclug-list at mn-linux.org > http://mailman.mn-linux.org/mailman/listinfo/tclug-list >